Unconjugated
AIM:
Telekin, isolated from the Chinese herb Carpesium divaricatum, has shown anti-proliferation effects against various cancer cells, including hepatocellular carcinoma cells. In this study, we investigated the anti-proliferation mechanisms of telekin in human hepatocellular carcinoma HepG2 cells in vitro.
METHODS:
HepG2 cells were treated with telekin. Cell viability was evaluated using MTT assay. Flow cytometry was used to measure cell cycle profiles, ROS level and apoptosis. The protein expression levels were analyzed with Western blotting.
RESULTS:
Telekin (3.75-30 μmol/L) dose-dependently inhibited the viability of HepG2 cells and induced l apoptosis. Furthermore, the treatment induced cell cycle arrest at G2/M phase, accompanied by significantly increased the phosphorylation of Cdc25A and Cdc2, and decreased Cyclin B1 level. Moreover, the treatment significantly stimulated ROS production, and increased the phosphorylation of p38 and MAPKAPK-2 in the cells. Pretreatment with the antioxidant NAC (2.5, 5, and 10 mmol/L), or the p38 MAPK inhibitor SB203580 (2.5 and 5 μmol/L) dose-dependently attenuated these telekin-induced effects in the cells.
CONCLUSION:
Telekin suppresses hepatocellular carcinoma cells in vitro by inducing G2/M phase arrest via activating the p38 MAPK pathway.
In this study, we investigated the underlying molecular mechanism for the potent cell cycle inhibition and pro-apoptotic effect of luteolin (2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-chromenone) on human non-small-cell lung carcinoma cell line A549. MTT assay showed that luteolin had obvious cytotoxicity on A549 with IC(50) of 40.2 μM at 48 h. Pro-apoptotic effect of luteolin on A549 cells was demonstrated by Hoechst 33258 staining assay and annexin V-FITC/PI double staining analysis. A great quantity of apoptotic cells and increasing G2 phase cells were observed by flow cytometry. Western blotting assay revealed that luteolin activated JNK, increased Bax, promoted procaspase-9 cleavage and activated caspase-3 at last. Assay using TNFα, an active agent of NF-κB, showed that pretreatment of A549 cells with luteolin could inhibit TNFα induced trans-nuclear of NF-κB. In summary, luteolin displayed a significant cytotoxic effect through cell cycle arrest and apoptosis induction in A549 cells. Pro-apoptotic effect was implemented via activating JNK and inhibiting translocation of NF-κB (p65). These results suggested that luteolin might have therapeutic potential against NSCLC.